howarmat said:

Almost all states allow a %. You can have the shop go darker usually too. I don't know of anyone who actually got a ticket for it either.

Here is the state by state breakdown:

http://www.tintdude.com/laws.html

MI seems like you can do just about any %.

I got a ticket and had to have mine removed. I have factory tint of NOTHING practically, but their tintometer thang said I was running at 17%. I didn't put the aftermarket tint on. I bought the truck used from a dealership that way. Just thought I'd add my 2 cents.

mrbrent said:

I have a 2006 Mustang GT and the Shaker 500 system and I pulled off the plastic face plate and it sits right on top of the Z1 screen and look stock. In the daylight you could figured it out if you spent some time looking but at night it is pretty tought to tell.

I got a faceplate from a broken mach 460 head unit and made a faceplate for my 02 mustang just like you ;) it's nearly impossible to tell unless you're sitting in the front seat.